A/C Request A Circuit
General electrical fault on the A/C compressor request input A. This input tells the ECM that the HVAC controller wants the A/C compressor engaged. With the input invalid, the ECM cannot enable the compressor clutch — A/C does not cool, idle-up compensation is not applied.
Affected components
- Ac request input a
- Hvac module
Common causes
- High likelihood: Open or shorted A/C request wire
- Medium likelihood: HVAC module not transmitting the request
Diagnostic notes
- The malfunction indicator lamp may illuminate
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.